


Silver Snow, Silver Scales

by cathrheas



Series: @cathrheas' Kinktober 2019 [25]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Dragon Fucking, Dragon Penis, F/F, Mating Cycles/In Heat, Spoilers for Church Route, we're in the last week of kinktober i dont give a fuck if y'all are judging me anymore
Language: English
Status: Completed
Published: 2019-10-26
Updated: 2019-10-26
Packaged: 2021-01-13 16:44:55
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,042
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21177722
Author URL: https://archiveofourown.org/users/cathrheas/pseuds/cathrheas
Summary: Catherine and Rhea's anniversary approaches, and Rhea starts acting strangely.





	Silver Snow, Silver Scales

**Author's Note:**

> (Day 25: Monsterfucking)
> 
> i have nothing to say for myself other than i enjoyed this thoroughly.
> 
> song: hi high by loona

Catherine wasn’t  _ fluffy _ or  _ romantic _ by anyone’s standards. She was, at the very most, considerate. It took Rhea by surprise when Catherine admitted she’d been counting the days until their one year anniversary.

“I’ve been counting down since six months, y’know,” Catherine said. 

“I must admit, I am honored you have put the effort into remembering. We are...four days away, are we not?”

“Three days and seventeen hours, but who’s counting?” Catherine winked, and a flush appeared on Rhea’s cheeks. “Ha. I am, I guess. Would you like to do anything special?”

“Ah, no...that is fine,” Rhea said. She smiled, a bit stiffly. “We can have tea in the morning, or something of that sort, but I will be quite busy that day. I apologize.”

“Oh,” Catherine said. She toed at the floor of Rhea’s office, shrugging. “Can’t be helped.” Rhea seemed solemn, genuinely upset, but Catherine sensed a little bit of relief, too. As if Rhea was afraid to argue about why she wasn’t available. Well, as much as Catherine loved Rhea, she rarely went down that easy. “Lady Rhea, I can’t help but wonder—”

“Monastery affairs,” Rhea sighed. “That is all. It is simply a matter of bad timing and the weight of responsibility. I am sure you understand, Catherine, that the well-being of Garreg Mach is incredibly important to me.”

“Of course, yes,” Catherine said quickly. “But...is it really stuff that can’t wait until the next day? Or done the day before? I just want to spend our anniversary...y’know. With you.”

“The day before and the day after...” Rhea mumbled to herself, as if to consider it. Then, she smiled. “I could, perhaps, schedule the day before and after our anniversary to be completely for you and you alone. That could be arranged. Would that not be better, anyway? Two days where we can revel in one another, free from distractions. I will set upon making it a reality, if that sounds acceptable to you.”

Catherine wanted to complain, but Rhea was well-meaning. She always was. Even if she didn’t quite grasp that the day before or the day after wasn’t as good as  _ the  _ day. She was doing her best. “Yeah. Sounds good, Rhea. I’m excited.”

* * *

To Rhea’s credit, she  _ was _ excited, and the day before their anniversary was full of surprises. Rhea was quite capable, Catherine learned. She was no weakling and no idiot, Catherine knew that, but...well, she was pampered by Seteth and the Knights to some extent. She seemed quite proud of herself for making dinner for her and Catherine all on her own, and having Seteth escort her to the garden every day so that she could work on making the perfect bouquet. It wasn’t all grand gestures, though. They spent the whole day quite leisurely, doing simple things that they rarely had time to do: lounging in Rhea’s bed, reading (although Rhea had to pick out the most action-packed fables to draw Catherine’s attention), feeding each other fruit...Rhea had even commissioned some musicians to play for them in the garden.

By the end of the night, though, Rhea had started acting strange. She was spacey, lost in her own head, and generally inattentive. Catherine was upset, knowing that she wouldn’t be able to see Rhea that much the next day, but more than anything, she was concerned. They were laying in Rhea’s bed, hand in hand, until Catherine noticed that Rhea’s breath was a bit...shaky.

“Lady Rhea? Are you alright?”

“I’m fine,” Rhea said. She smiled up at Catherine. For a moment, Catherine saw a flash of  _ something _ in her eyes, like they had changed shape. But it was just her imagination, surely. “I suppose I am a little exhausted. We were up quite early today.”

“Yeah, that’s true. Let’s go to sleep, then.”

“Er, Catherine...perhaps you should sleep in your quarters tonight,” Rhea said. 

There was an uncomfortable amount of pity in her voice. Catherine’s shoulders sagged. “What? Why? Look, I know I snore a little, but—”

“No, no. It is just that...I will be getting up quite early, and I do know you enjoy sleeping in. I will be waking before sunrise.”

“I do too, for training.”

“Yes, well, I believe I will be rising earlier.”

“Rhea, you can’t be serious. It’s one thing to skip out on our anniversary, but you can’t even let me sleep here tonight? Besides, I thought we were getting tea in the morning.”

“Yes, I had hoped so, but circumstance has made things turn out differently,” Rhea said. She was so tentative, so meek. As if Catherine couldn’t see a lie from a mile away. But what was she hiding? “Catherine, please, humor me. I apologize. But the day after, I swear, it will be even better than today.”

Rhea cupped Catherine’s cheeks, kissed the tip of her nose. Catherine didn’t react. “There’s something up. You’ve been acting fishy.”

“Nothing is wrong.”

“Bullshit.”

“Catherine,” Rhea exclaimed. “Please, be civil.”

“I’m trying! But...you’re hiding something, and I don’t like it,” Catherine said. Rhea was about to speak again, but Catherine held up her hand. “Fine. Fine, I’ll play along. I don’t like it, but it seems like something is forcing your hand. Am I right? You don’t want to lie to me, right?” Rhea didn’t say anything. “Okay. I’m choosing to believe that you’re doing this against your will, since you won’t say. Since you want me gone, I’ll go.”

“Don’t say it like that,” Rhea said, softly, but Catherine was already getting out of bed and walking towards the door. “Catherine, I swear, the day after, I will tell you the truth.” Catherine paused, turning around to look at Rhea. Rhea seemed at the end of her rope, tired and sullen. “I mean it. But tomorrow...it was truly a coincidence. It truly has nothing to do with you. But I must attend to something that is out of my control.”

“I’m holding you to your promise,” Catherine warned. “So don’t hold back on me.”

“I love you,” Rhea said.

No matter how frustrated she was, Catherine would sooner die than leave a confession from Rhea returned. “I love you too, Rhea. I’m counting on you, so...I just hope whatever you have to do tomorrow is worth it.”

* * *

Catherine went back to her room like a good girlfriend would do, but she couldn’t fall asleep for a while. She didn’t realize until her head hit her pillow that Rhea was quite possibly lying to her. She came clean about keeping a secret, but she was so horribly vague that Catherine felt like a fool for letting it go so easily.

The sun rose, and Catherine  _ did _ end up sleeping in, but it was besides the point. When she rose, she decided that she was going on a mission. At the very least, Rhea was kind enough to give her their anniversary off, so she didn’t have to worry about working while investigating.

She started in the audience hall. Rhea wasn’t there, so she moved to her office, where she found Seteth. He was sitting in her chair, looking over papers. He looked up at Catherine with a taut smile. “Catherine. Happy anniversary.”

“Some anniversary. I can’t even see her.”

“Yes, it is truly a shame,” he said, shaking his head. “To think she would fall ill at a time like this...”

“Ill?”

“Yes...?”

Catherine approached the desk, putting her hands on it. “She told me she was busy with monastery stuff today.”

“Well,” Seteth said. He cleared his throat. “She was, but then she fell ill.”

“Seteth, I thought we were pals. Just tell me the truth.”

“I cannot recall a timeline in which I have ever been your ‘pal’.”

“Well, you are now. Tell me where Rhea is and what’s going on,” Catherine demanded.

Seteth looked down at his papers, then at the ceiling, then Catherine. He sighed. “She  _ is _ ill. In a way. I can guarantee you, she would not like to be bothered.”

“If she’s sick, I want to be comforting her,” Catherine said.

“The kind of comfort she needs is not the kind that anyone would wish to supply,” Seteth shuddered. “Trust me.”

“I’ll decide that for myself. Just tell me where she is!”

Seteth palmed his eyes. “Fine, but do not blame me if you do not enjoy what happens next,” he said, teeth clenched. “Oh, Goddess, please help me survive Rhea’s wrath when she finds out I’ve disclosed this...”

* * *

Rhea was in the Red Canyon. It made sense, given what Catherine knew about her origins, but it seemed strange. Rhea was skipping out on her and Catherine’s anniversary to chill out in a cave in Zanado? It was unfair, nonsensical. Seteth told her to “prepare herself” before going, but Catherine didn’t care what she saw. She just wanted to know the truth.

Catherine followed Seteth’s instructions, and came to the mouth of a cave. It was chilly, dark, moist. As Catherine stepped in deeper, she started to wonder if Seteth was playing a joke on her. It was unlikely, but...why would Rhea be there, of all places?

Eventually, the only light disappeared. Catherine kept walking, until finally, she came to a clearing in the cave. There was a large hole in the ceiling of the cave there, letting sunlight in. In the back of the cave was a large rock formation, but nothing else. Catherine wasn’t  _ scared, _ of course, but she wanted to turn tail and head back to the monastery. But she wouldn’t leave without making sure Rhea was okay. “Lady Rhea?”

Catherine stopped in her tracks when the ground started to rumble beneath her, like an earthquake. She took a few steps back, reaching for the hilt of Thunderbrand as the rocks in the cave began to move.

Then, a green glow began to emanate from the back of the cave where the rock formation was. In a rush of wind, the rocks revealed themselves to be much more than that; wings sprouted, and the creature that had unveiled itself surged forward. Catherine’s breath was knocked out of her as she was pinned to the ground by the creature’s hand, a claw digging into her chest.

“Why are you here? Answer me,” the creature roared.

Catherine was paralyzed by fear, unable to respond. She couldn’t move or breathe under the monster’s hand, but somehow, she felt as if it wasn’t even using its full strength. As her senses came back to her, though, the monster’s words echoing in her brain, she noticed something familiar in the monster’s voice. With her last puffs of breath, Catherine said, “Rh-Rhea? Is this you? Could it be? It’s Catherine! Hey! It’s me! Look, your hand is a little—uh...”

“You...” The monster—a fearsome dragon—was breathing heavily, its eyes nearly bulged with what Catherine hoped wasn’t anger. It had four horns, stretching off of its head, and countless teeth. Catherine took in Rhea’s new form, regaining her ability to breathe as Rhea’s hand lifted off of her chest. Was that recognition in the beast’s gaze?

Catherine scrambled backwards. She wanted so badly to reach for her sword, but Rhea backed away, as if to show that she was being peaceful. Catherine stood, and Rhea backed away further. “Hey, calm down, it’s okay. It’s you, isn’t it? Rhea? Or am I going crazy...”

“I am not Rhea,” the beast said, but the voice was undoubtedly Rhea. Catherine would know it, even through the deep, bloody throat of a dragon. “Go away from here.”

“No! I can’t leave you, not like...this...” Catherine didn’t know what to say. Should she leave? But even if she wanted to, she was so numb with terror, she wasn’t sure if she would be able to run. Something about those  _ eyes _ were so hypnotizing, as if to freeze her into place. She looked Rhea over, watched her chest puff in and out as she breathed.

Then, she saw...it. A massive protrusion from Rhea’s underbelly. It was silver, like Rhea’s scales, up until the head, where it became a bright, fleshy pink. Rhea growled when she saw Catherine ogling it, but a string of pre-cum was leaking from her tip and dripping to the floor of the cave.

“Go away,” Rhea said.

“That thing is...huge.”

“Leave, or I shall make you.”

“No, no, this is fine,” Catherine said. “I’m just...a little confused...are you in heat or something? Do dragons do that?” Rhea didn’t respond, her tail swinging aggressively. One hit from it would have sent Catherine to meet her maker, surely. But Rhea didn’t seem to be violent, as far as Catherine could see. Just agitated. “No wonder you’re so worked up. I would be too, if I had to be horny in a cave for a whole day...is that why you left? You didn’t want me to see you like this?”

“You will despise me,” Rhea said. There was a hint of sadness behind her voice. “You should not have come here...”

“Easy does it.” Catherine walked forward, and Rhea tensed; her muscles were so large that Catherine could see the ripple of every scale. “I don’t want you to suffer—”

Rhea rushed Catherine again, knocking her to the stone floor of the cave. “I gave you the chance to leave, but you would not listen! Foolish...foolish, foolish girl. I could have had my fill of you long ago, but I had taken pity upon you. It seems you do not want it. I will destroy you. Do you understand me?”

Rhea leaned down, her nose mere centimeters away from Catherine’s face. Catherine could feel the warmth of her heaving breaths. More than that, she could feel Rhea’s shaft against her leg. It wasn’t  _ impossibly _ big, but...it was larger than that of any human, that was for sure. “I-I understand,” Catherine said.

“Leave. This will be your final chance,” Rhea said, but she did not lift her hand.

She must have anticipated Catherine’s response. “I won’t leave. Not until...you’re satisfied. It’s our anniversary, right? So I should—”

Rhea roared, but Catherine couldn’t tell if it was in frustration, or anger, or excitement, or a mix of all three. Whatever it was, it made Catherine’s heart beat a mile a minute. Did Rhea even recognize her fully? The glazed over look in her eyes indicated that she didn’t. “You will receive no more pity from me.”

Rhea’s claws tore into Catherine’s armor, her clothes. Catherine cried out as Rhea’s claws grazed her skin, leaving a red mark. Not quite bleeding, but burning. Rhea gave no pause, continuing until Catherine was bare before her. It was only then that she lifted her hand from Catherine’s chest, moving up Catherine’s body so that her dick was closer to Catherine’s entrance.

Catherine was surprised to feel herself being so wet when her pussy was exposed to the air. But had she ever been dominated by anyone in such a way? Rhea was always so gentle, so loving when they were in bed together. To see Rhea being so aggressive and so needy was...it was different. It was a turn-on.

“You’re a suitable mate,” Rhea rumbled. There was no emotion in her voice, though, as if Catherine were merely a piece of meat. Catherine arched her back a bit when she felt Rhea’s tip pressing against her, but she had no time to adjust. Rhea pushed inside of her, letting out another roar as she did so. Rhea was so loud and ferocious that Catherine couldn’t hear herself moan. Rhea’s growls echoed off the walls of the caves as her dick speared Catherine. There was an overwhelming pain at first, even though Catherine was wet. She reached up to grip Rhea’s scaly forearm; she was surprised by how warm it was. 

Through each snarl, Catherine could hear the slightest hint of Rhea’s true voice, but it was always overshadowed by a draconic drone. Catherine arched hard into the stone, trying hard to make her body adjust to the monstrous cock inside of her. Rhea was relentless in her thrusts. Catherine could hear how relieved she was at the pleasure she was finally receiving. Catherine couldn’t help but wonder if Rhea even had a way to relieve herself when she was in draconic form...did she really just suffer through it when her heat came through?

Catherine held Rhea’s scales tighter when the thrusts got faster, even though they were sharp enough to wound her. Rhea slamming deeper and faster into her gave her even less time to gather herself. Before she knew it, though, the pain subsided, and she was left with a feeling of fullness and warmth. Rhea was on top of her,  _ inside _ of her, a Rhea that she had never seen before. It was exhilarating. 

And no matter how scary it was at first, the hottest part was how much Rhea didn’t care. Catherine had been writhing in pain moments before, unable to adjust...then her cries of terror turned to cries of pleasure, and Rhea still had hardly any reaction. She just kept thrusting and thrusting, just glad to be in the possession of someone—something—to fuck. Catherine was nothing more than that, and her pleasure was trivial. Despite that fact, it felt  _ good. _ Catherine wouldn't have cared if Rhea killed her on the spot after she got her fill. Rhea's cock was so massive, every inch of it was touching every inch of Catherine. There was no escape from that overwhelming feeling of fullness, of possession.

As soon as the thought passed Catherine's mind, Rhea began to roar again, that time a bit more contained. “My mate...Catherine,” Rhea said, with an underlying purr to her voice. 

“Rhea,” Catherine said, with a heavy shudder. Her own voice had never sounded so weak, so foreign. But that was what Rhea did to her, no matter what form she was in. Catherine had always felt a bit out of character in Rhea’s arms, but when Rhea was looking down at her with reptilian eyes and rows upon rows of dangerous teeth, Catherine felt like she wasn’t even in her own body anymore. No, Rhea had overtaken it. There was no need to resist, anyway; she didn’t want to. Rhea must have truly been crazy, thinking Catherine would turn down a feeling so different, so amazing.

Rhea’s aggression seemed to ease, but she was still just as rough as before. Her grip loosened a bit, allowing Catherine to grind against her more effectively. Rhea responded well to Catherine’s eagerness, her lips pulling back into a wicked grin. “Yes...submit to me. Excellent...”

Had Rhea always been that possessive, or was that the dragon’s blood talking? Either way, Catherine was loving it. She loved serving Rhea, even if that meant being pinned to the ground and fucked senseless. Catherine wasn’t used to Rhea being so forward about what she wanted, but now that she’d had a taste, she wanted nothing more than for Rhea to dominate her every night until the end of time.

Catherine felt her orgasm approaching just as Rhea started to tense, her scales ruffling. “My mate,” Rhea repeated, almost hypnotized. Catherine gasped at the words, holding onto Rhea as tight as she could manage without impaling herself on Rhea’s scales. Rhea merely huffed at Catherine, so indifferent to Catherine trembling and moaning beneath her. 

Even though she was still pounding Catherine with force, Rhea seemed hesitant, slowing down considerably. The somewhat comfortable rhythm Rhea had settled into was soon discarded in favor of staggering thrusts that came periodically. Catherine didn’t realize until Rhea let out a deafening roar, her claws digging into Catherine again, that Rhea was climaxing. Her cum was thick, hot, leaving an almost burning sensation on Catherine’s walls. The insane roar died down to a growl as Rhea emptied herself. Catherine was wiped out by then, laying back against the jagged stone floor and letting Rhea do as she wished. 

Rhea growled one last time, so deep and powerful that Catherine felt it shake her soul, before settling on top of Catherine. She was gentle, amazingly, not letting her full weight crush Catherine. “This will hurt,” Rhea said.

Catherine lifted her head a bit, shocked by how human Rhea suddenly sounded. Mere moments after, she felt the joyful buzz between her legs turning into a sharp pain as Rhea withdrew from her. She put one hand on Rhea’s forearm, used the other to grab a horn, holding on tight until Rhea’s shaft had left her. Soon after, Rhea’s cum started seeping out, forming a puddle on the floor.

“Fuck,” Catherine sighed. She stared at the roof of the cavern, so high up and wide that it looked black. “I can’t believe this just...I...”

“Rest,” Rhea said. She sounded more like herself, but she was still demanding. She was intent on not giving Catherine a choice; she lifted Catherine’s upper body with her nose, urging her to sit up, then wrapped her massive form around Catherine. Rhea’s scales had seemed quite warm earlier, but they were cool compared to Catherine’s heated skin. Catherine leaned into her. It wasn’t the most comfortable, but...it was Rhea. Catherine could feel her body swell with every breath. “Go on. Rest.”

“Alright, alright...”

As if she could hold her eyes open any longer. She was so drained, she didn’t even notice the pain or the scratches or the adrenaline. It all felt like a dream, almost...

* * *

"Happy anniversary, Catherine.”

Catherine couldn’t move. She felt like a sack of rocks, thrown onto the bed without a second thought. She managed to open her eyes and look up, and she instantly recognized Rhea. Her honey-sweet voice, her loving eyes...

Wait. It was their anniversary? 

“What day is it? What time is it?” Catherine lifted her head, rubbing her neck. “I smell tea...”

“O-oh, yes, I made some. I figured you’d want some, when you woke up,” Rhea said. “Would you?”

“Um...yeah, sure,” Catherine said. “What day is it?”

“...The fifteenth.”

“...Our anniversary was on the thirteenth.”

“Y-yes, I know. You’ve been resting for a while now,” Rhea said, averting her eyes. “Um...Catherine, I apologize for what...happened. In the cave. But, in order to be fair to myself, I must point out that I  _ did _ warn you not to pry—”

“Wait, what? Oh my gods. Was that real? You fucked me as a  _ dragon,  _ in real life? Holy—”

Rhea blushed madly, grasping Catherine’s hands. “P-please, don’t say it like that. I-I can’t help it. I tried my hardest to keep it a secret, or make it go away, but I couldn’t.”

“No, I’m not mad. That was fucking awesome! Can you do that all the time? Like, or is it just then?”

“Catherine! I don’t even know why you’d ask something like that,” Rhea said, frowning. “You must have misconstrued your memories of what happened. That had to have been horrifying, or...borderline  _ traumatizing. _ Why would you want that again?”

Catherine scoffed. “Come on, Rhea. You’d never hurt me. Even when you were roaring like a maniac, you still gave me a chance to leave. And then you brought me tea right after! I wouldn’t have asked if I didn’t like it.”

Rhea held Catherine’s teacup in her hands, looking down into it with solemn eyes. Catherine should have known from the moment she saw Rhea in the cave that Rhea would never have harmed her, no matter what state of mind she was in. No, Rhea was too protective, too loving. Catherine had no doubt about it. Rhea seemed to have come to terms with it too, looking up at Catherine with nervous eyes. “Well, it’s only once a year. On our anniversary...”

“Isn’t that grand timing! Think of it as an anniversary gift,” Catherine said. She took her tea from Rhea’s hands. The cup was hot; just the heat coming off of it soothed her aching muscles. “You’ve got a whole year to think about it. But I just want you to know that I enjoyed that, Rhea. So, happy anniversary, indeed...mate.”

**Author's Note:**

> obligatory dragon dick because, fire emblem.
> 
> also has anybody noticed that the cathrhea kinktober fics are always the long ones? well, stop noticing. i can't make my bias too obvious.


End file.
